The present invention relates generally to range sensing and more particularly to ultrasonic range sensing and temperature sensing in road finishing applications. In construction using asphalt and concrete materials (e.g., road finishing, paving, etc.) various systems and methods for sensing the distance to a surface (e.g., a road) have been used.
Contacting and non-contacting systems have been used. Contacting systems suffer in that they are prone to damage and breakage. Prior non-contacting systems are not accurate enough. These systems generally employ a range sensor, such as an ultrasonic sensor, to measure the distance from the construction vehicle or sensing unit to the road surface. In some systems more than one homogenous sensor is used to measure distances to the surface from the sensing unit. These measured distances are averaged to determine an approximate distance between the sensing mechanism and the surface.
In some cases, these sensing units or construction vehicles include some apparatus for temperature sensing. An example of a commonly used temperature sensor is a U-shaped metal attachment to the sensing apparatus that extends toward the road surface. The attachment is used to measure the temperature at the road surface.
The prior range sensing set-ups often provide inaccurate measurements and/or inconsistent sensing because the construction vehicle and/or the sensors and sensing unit may be too close or too far away from the road surface. That is, the sensors may not be in their optimal performance range. Accordingly, improved systems and methods for range sensing are needed.